Food sauce dispensing cartridges are used throughout the food service industry for dispensing a measured quantity of sauce on a food item. As an example, in fast service restaurants, a large volume of food items must be prepared for customers in a relatively short around of time. Meeting this demand presents a significant challenge; consistent food quality can only be achieved by dispensing the correct amount of sauce, but the fast pace of preparing food items leaves little time to carefully measure dispensed amounts. The use of handheld dispensing guns with food sauce dispensing cartridges has enabled consistent and fast dispensing of sauce amounts to allow greater quantities of food items to be prepared within a narrow timeframe. The exact quantity of sauce dispensed by the cartridge is controlled by valves formed in the dispensing end of the cartridge and the degree of motion of the dispensing gun acting on a plug in the cartridge being advanced towards the dispensing end. Each time a trigger of the dispensing gun is pulled, the gun advances the plug a consistent distance.
Typically, food sauce dispensing cartridges are fabricated from paper stock with opposing ends folded together in a continuous loop sidewall such that the ends overlap one another and are adhered together to form the cartridge in a cylindrical shape. This overlap creates a sideseam that runs the length of the container. Additionally, the outer and interior surfaces of the cartridge are typically coated with a thermoplastic liner. The plug is most often formed of a thermoplastic or other similar plastic.
While advancements have been made in the design and manufacture of end caps containing the values disposed at the dispensing end of the dispensing cartridges, problems remain with methods of sealing the plug with the cartridge to prevent leaks at the plug. Although plugs are often bonded with the interior surface of the dispensing cartridge before use with a dispensing gun, the bond must release enough to allow the gun to advance the plug through the cartridge while at the same time maintaining a seal such that food sauce within the cartridge may not pass by the peripheral edge of the plug and escape out of the containment region. One common method of bonding the plug is to heat the flanged perimeter edge of the plug (e.g., with hot air) such that the plastic melts and bonds with the thermoplastic liner of the cartridge. This method, however, does not provide a leak proof seal for typical dispensing cartridges. This is because the internal sideseam of the cartridge causes the interior diameter thereof to vary as much as the sidewall thickness of the container from a point where the sidewall overlap occurs to a point adjacent to the sideseam. The plug on the other hand has a consistent diameter around the peripheral edge, and the melting of the flanged edge is not sufficient to fill a gap created between the peripheral edge and the cartridge sidewall at a point immediately adjacent to the sideseam. Thus, as the dispensing gun advances the plug, food sauce escapes the cartridge not only at the intended dispending end, but also by bypassing the periphery of the plug along the sideseam towards the opposing end. Also, the gap may present an additional path for contaminants to enter the containment region of the cartridge.